The invention relates to a rotary drive for actuating a valve element of a valve fitting, having a housing, which has a drive device and a pivot-mounted driven shaft which can be driven by the drive device and which can be coupled to the valve element, and a position detection device for detecting a position of the driven shaft, wherein the position detection device has a magnet module attached to the driven shaft in a torque-proof manner and a sensor module which is fitted onto or into the housing and is adapted to detect a magnetic field measurement value according to the magnetic field generated by the magnet module.
A rotary drive of this type can be attached to a valve fitting or process valve in order to actuate a valve element of the valve fitting, the valve element being located in a process fluid, and in this way manipulate and/or block a fluid flow. The driven shaft of the rotary drive is mechanically coupled to a spindle of the valve fitting. The spindle in turn is mechanically coupled to the valve element of the valve fitting, so that the valve element is actuated via an actuation of the spindle. The valve element of the valve fitting is, for example, formed as a damper, butterfly valve, plug valve, spherical valve or ball valve.
From U.S. Pat. No. 6,135,147A, a rotary drive is known, having a monitoring arrangement which is attached to the top of the housing of the rotary drive and which serves to detect the position of the driven shaft. For this purpose, an indicating device provided with magnets is fastened to the driven shaft protruding out of the top of the housing, this indicating device rotating together with the driven shaft. In addition, magnetic switches, which depending on the position of the magnets cause light-emitting diodes to be fed with current, are provided in a monitoring arrangement which is arranged on the top of the housing next to the indicating device.